In general, a stacked core, for example, a motor stacked core is formed in the following manner. A thin-strip material intermittent carried into a press die by a feeder, by means of the thin-strip material intermittent proceeding through a plurality of pressing and/or punching process cavities of the press die, mounted to a press machine. A thin-sheet plate is then constantly intermittent stacked to a prior stacked member immediately after being punched out from the thin-strip material as a sheet of plate, pressed and interlocked to the prior stacked member in the stacking cavity of the press die. Since a thickness of the each punched out thin-sheet of plate vary within itself, due to prior pressing and/or punching processes, as a conventional method, rotate in a predetermined angle a stacking cavity device, a block having the stacking cavity and rotates in the press die. The thin-sheet of plate is interlocked to the prior stacked member with pressure. Thereafter, a thickness of the stacked core is within a predetermined thickness. An equipment of angle indexing apparatus for driving the stacking cavity device in the predetermined angle is set to the press machine, which is driven by continuous rotational power, transmitted from the driving unit of the press machine.
The angle indexing apparatus is driven for rotating the stacking cavity device during a Feeding-Phase period of time (by means of a Crank Angle from 270° to 90°) of the press machine as well as the thin-strip material is carried to next pressing and/or punching process cavity. When the angle indexing apparatus completes rotating the stacking cavity device (by means of the Crank Angle at 90° of the press machine), the press machine starts its Machining-Phase and runs in to a Machining-Phase period of time (by means of the Crank Angle from 90° to 270°) of the press machine. During the Machining-Phase period of time, neither the angle indexing apparatus drives stacking cavity device nor is the thin-strip material carried to next process cavity. Thereafter, the thin-strip material at each cavity is pressed/punched and at the stacking cavity, a thin-sheet of plate is punched out from the thin-strip material, pressed and interlocked to the prior stacked member.
The angle indexing apparatus is set as to rotate at in the Feeding-Phase period of the press machine, includes a cam unit having a cam driven by an input shaft, and an indexing unit having an output shaft and a plurality of cam rollers contacted to the cam unit. By the pivoting cam rollers which rotate by the cam unit, in a predetermined angle, and thereby, the output shaft is rotated in the predetermined angle so that the angle indexing apparatus drive the stacking cavity device.
In a conventional stacking core apparatus, an input shaft of an angle indexing apparatus is connected to a driving unit of a press machine by a transmission member. Thus, the input shaft of the angle indexing apparatus continuously rotates at a constant rotational speed, synchronized to a constant rotational speed of the driving unit of the press machine. Hence the output shaft of the angle indexing apparatus has been equally intermittent driven synchronized to the Feeding-Phase period of the press machine, by means of the output shaft of the angle indexing apparatus rotates in the predetermined angle during the Feed-Phase period of time (i.e.; Crank the Angle from 270° to 90°) of the press machine, and is in a non-rotational state during a Machining-Phase period of time (i.e.; the Crank Angle from 90° to 270°) of the press machine.
In the above conventional stacking core apparatus, the rotation of the output shaft of the angle indexing apparatus stops rotating when the Feed-Phase period of time completes (i.e.; at the Crank Angle of 90°) at the same time, as well as in the same time the Machining-Phase period of time starts. That is, when the Machining-Phase period of time starts, each pilot protrusion arranged at an upper portion of the press die immediately jump into pilot protrusion guide holes respectably to predetermined guide holes arranged in each cavity device, when the stacked member is rotated and rotation is stopped. However, in an event of the press machine is operated at a high-speed, when the Feeding-Phase period of press machine completes and in the same time the Machining-Phase of period of the press machine starts, the pilot protrusions immediately jump into their pilot guide holes, but the stacking cavity device is still in pivoting motion and is not in a settlement state. When arc of pivoting pilot guide holes vary since the stacking cavity device is still in pivoting motion, when pilot protrusions jump into other than pilot guide holes, pilot protrusions are broken and/or damaged. For this reason, a high-speed operation can not be achieved.
An example of conventional method in order to achieve the high-speed operation, is to set the angle indexing apparatus output shaft rotational less than an angle of 180° (e.g., 150°, 120°, etc.) in respect to the input shaft rotation an angle of 180°, in order to obtain a time to attenuate the pivoting motion when the rotation is stopped. However, this additional mechanical structure change leads to a reduction of strength of the angle indexing apparatus and also to its transmitting rotational torque to the stacking cavity device, and thus it is impossible to achieve a high-speed operation.